LM431CIMX - Fairchild Semiconductor Corporation

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 1

December 2012

LM431A / LM431B / LM431C

Programmable Shunt Regulator

Features

• Programmable Output Voltage to 36 V

• Low Dynamic Output Impedance 0.2 Ω (Typical)

• Sink Current Capability: 1.0 to 100 mA

• Equivalent Full-Range Temperature Coefficient of

50 ppm/°C (Typical)

• Temperature Compensated for Operation Over Full

Rated Operating Temperature Range

• Low Output Noise Voltage

• Fast Turn-on Response

Description

The LM431A / LM431B / LM431C are three terminal out-

put adjustable regulators with thermal stability over the

full operating temperature range. The output voltage can

be set to any value between VREF (approximately 2.5 V)

and 36 V with two e xternal resis tors. These dev ices have

a typical dy na mi c ou tpu t imp eda nc e of 0.2 Ω. Active out-

put circuit provides a sharp turn-on characteristic, mak-

ing these devices excellent replacements for Zener

diodes in many applications.

TO-92

8-SOIC

1. Ref 2. Anode 3. Cathode

1.Cathode 2.3.6.7.Anode

4.5.NC 8.Ref

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 2

Ordering Information

Block Diagram

Figure 1. Block Diagram

Part Number Operating

Temperature

Range

Output Voltage

Tolerance Top Mark Package Packing Method

LM431CCZ

-25 ~ +85°C

0.5% LM431CCZ TO-92 Bulk

LM431CCMX LM431CCM 8-SOIC Tape and Reel

LM431BCZX 1% LM431BCZ TO-92 Tape and Reel

LM431BCZXA LM431BCZ TO-92 Ammo

LM431BCMX LM431BCM 8-SOIC Tape and Reel

LM431ACZ 2% LM431ACZ TO-92 Bulk

LM431ACZX LM431ACZ TO-92 Tape and Reel

LM431ACMX LM431ACM 8-SOIC Tape and Reel

LM431CIMX

-40 ~ +85°C

0.5% LM431CIM 8-SOIC Tape and Reel

LM431BIZX 1% LM431BIZ TO-92 Tape and Reel

LM431AIZ 2% LM431AIZ TO-92 Bulk

LM431AIMX LM431AIM 8-SOIC Tape and Reel

CATHODE

ANODE

REFERENCE

CATHODE (K)

ANODE (A)

REFERENCE (R)

2.5 Ref

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 3

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be opera-

ble above the re co mmen ded operating conditions and stressi ng the part s to these levels is n ot re commended. In addi-

tion, extended exposure to stresses above the recommended operating conditions may affect device reliability. The

absolute maximum ratings are stress ratings only. Values are at TA = 25°C unless otherwise noted.

Recommended Operating Conditions

The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended

operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not

recommend exceeding them or designing to Absolute Maximum Ratings.

Symbol Parameter Value Unit

VKA Cathode Voltage 37 V

IKA Cathode Current Range (Continuous) -100 ~ +150 mA

IREF Reference Input Current Range -0.05 ~ +10 mA

PDPower Dissipation

M, Z Suffix Package 770 mW

TOPR Operating Temperature Range LM431xC -25 ~ +85 °C

Operating Temperature Range LM431xI -40 ~ +85 °C

TJJunction Temperature 150 °C

TSTG Storage Temperature Range -65 ~ +150 °C

Symbol Parameter Min. Typ. Max. Unit

VKA Cathode Voltage VRef 36 V

IKA Cathode Current 1.0 100 mA

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 4

Electrical Characteristics

Values are at TA = 25°C unless otherwise noted.

Notes:

1. LM431xC: TMIN = -25°C, TMAX = +85°C.

LM431xI: TMIN = -40°C, TMAX = +85°C.

Symbol Parameter Conditions LM431A LM431B LM431C Unit

Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.

VREF Reference

Input Voltage VKA = VREF,

IKA = 10 mA 2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508 V

ΔVREF/

ΔT

Deviation of

Reference

Input Voltage

Over-

Temperature

VKA = VREF,

IKA =10 mA

TMIN ≤ TA ≤ TMAX(1) 4.5 17.0 4.5 17.0 4.5 17.0 mV

ΔVREF/

ΔVKA

Ratio of

Change in

Reference

Input Voltage

to the

Change in

Cathode

Voltage

IKA =

10 mA

ΔVKA =

10V-VREF -1.0 -2.7 -1.0 -2.7 -1.0 -2.7

mV / V

ΔVKA =

36V-10V -0.5 -2.0 -0.5 -2.0 -0.5 -2.0

IREF Reference

Input Current IKA = 10 mA,

R1 =10 kΩ, R2 = ∞1.5 4 1.5 4 1.5 4 μA

ΔIREF /

ΔT

Deviation of

Reference

Input Current

Over Full

Temperature

Range

IKA = 10 mA,

R1 = 10 kΩ, R2 = ∞

TA = Full Range 0.4 1.2 0.4 1.2 0.4 1.2 μA

IKA(MIN)

Minimum

Cathode

Cur-

rent for

Regulation

VKA = VREF 0.45 1.0 0.45 1.0 0.45 1.0 mA

IKA(OFF)

Off - Stage

Cathode

Current

VKA = 36 V,

VREF = 0 0.05 1.0 0.05 1.0 0.05 1.0 μA

ZKA

Dynamic

Impedance VKA = VREF,

IKA =1 to 100 mA

f ≥ 1.0 kHz 0.15 0.5 0.15 0.5 0.15 0.5 Ω

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 5

Test Circuits

Figure 2. Test Circuit for VKA= VREF Figure 3. Test Circuit for VKA ≥ VREF

Figure 4. Test Circuit for IKA(OFF)

LM431

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 6

Typical Performance Characteristics

Figure 5. Cathode Current vs. Cathode Voltage Figure 6. Cathode Current vs. Cathode Voltage

Figure 7. Change In Reference Input Voltage vs.

Cathode Voltage Figure 8. Dynamic Impedance Frequency

Figure 9. Small Signal Volt a ge Amplification vs.

Frequency Figure 10. Pulse Respo nse

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 7

Typical Performance Characteristics (Continued)

Figure11. Stability Boundary Conditions

100p 1n 10n 100n 1? 10?

100

120

140

A VKA = Vref

B VKA = 5.0 V @ IK = 10mA

C VKA = 10 V @ IK = 10mA

D VKA = 15 V @ IK = 10mA

TA = 25oC

IK, CATHODE CURRENT(mA)

CL, LOAD CAPACITANCE

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 8

Typical Application

Figure 12. Shunt Regulator Figure 13. Output Control for Thre e-

Terminal Fixed Regulator Figure 14. High-Current Shunt

Regulator

Figure 15. Current Limit or Current Source Figure 16. Constant-Current Sink

VO1R1

-------+







Vref

LM431

VOVref 1R1

-------+







LM431

VO1R1

-------+







Vref

LM431

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 9

Physical Dimensions

Figure 17. 3-Lead, TO-92, Molded, Standard Straight Lead

Package drawings are provided as a service to customers cons idering Fairchild components. Drawings may change in any manner

without notic e. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or

obtain the most recent revision. Package specifications do not expan d the terms of Fairchild’s worldwide terms and condition s, specifically the

warranty therein, which covers Fairchild produ cts.

Always visit Fairchild Semiconduct or’s online packaging are a for the most recent package drawings :

http://www.fairchildsemi.com/packaging/.

TO-92 Bulk Type

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 10

Physical Dimensions (Continued)

Figure 18. 3-Lead, TO-92, Molded, 0.200 in Line Spacing Lead Form

Package drawings are provided as a service to customers cons idering Fairchild components. Drawings may change in any manner

without notic e. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or

obtain the most recent revision. Package specifications do not expan d the terms of Fairchild’s worldwide terms and condition s, specifically the

warranty therein, which covers Fairchild produ cts.

Always visit Fairchild Semiconduct or’s online packaging are a for the most recent package drawings :

http://www.fairchildsemi.com/packaging/.

For current tape an d reel specifications, visit Fair child Semiconductor’s online pac kaging area:

http://www.fairchildsemi.com/products/discrete/pdf/to92_tr.pdf.

TO-92 Ammo Type, Tape and Reel Type

LM431A / LM431B / LM431C — Programmable Shunt Regulator

LM431A / LM431B / LM431C Rev. 1.1.0 11

Physical Dimensions (Continued)

Figure 19. 8-Lead, SOIC, JEDEC MS 0-12, 0.150 inch Narrow Body

Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner

without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or

obtain the most recent revision. Package specificatio ns do not expand t he terms of Fairc hild’s worldwide terms and c onditions, specifically the

warranty therein, which covers Fairchild p roducts.

Always visit Fairchild Semic onductor’s online packag ing area for the most recent package drawings:

http://www.fairchildsemi.com/packaging/.

For current tape an d reel specifications, vis it Fairchild Semicond uctor’s on line packaging area:

http://www.fairchildsemi.com/products/discrete/pdf/soic8_tr.pdf.

8-SOIC

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Rev. I63